Don't imagine you would find ice that far north at this time of year (end summer). Sea temperature in this region likely to be 14 degrees.
South Western Australia
The fairly high density of the debris suggests it is from a common source and recent. Stuff from Banda Aceh tsunami (in 2004) wouldn't still be floating around in close formation.
I wonder if drift analysis is going to be much use at this stage. They had debris within a few days with AF447, and even that didn't really help find the wreckage. After a couple of weeks? - and particularly when the search has been cancelled due to poor weather (mainly due to low cloud base, but there was also a high sea state).
Perhaps the main use of finding wreckage will be to confirm the plane is somewhere in the South Indian ocean. The nature of debris will perhaps help experts determine the nature of crash - controlled ditching or high speed entry.
Finding a body with a phone containing a message or video would be very helpful. I suspect this is very unlikely however.
Searching for the pingers seems a long shot given the area involved, the difficult location, and the time remaining. And thats assuming the damn things are working. I have the feeling they would have to be very lucky.
If this was a deliberate act, someone would have done a fair bit of research. Hypoxia, human physiology, altitude medicine, depth of Indian ocean, current information for this area, Australian SAR capabilities, shipping routes etc.
It would certainly be worth checking peoples computers for evidence of such searches. This would be easy for crew, but would obviously be difficult for the passengers.
Does anyone know if it is possible to search back in the reverse direction? Can you search Google for someone who has searched what would be an unusual collection of unrelated things? I guess this would be looking for a different needle in a different haystack. However everything is looking like a long shot right now.